Add Fresh Blueberries (3 cup), Water (1/2 cup), Agave Syrup (1/3 cup), Chili Powder (1/2 teaspoon), Kosher Salt (1/4 teaspoon), Cayenne Pepper (1/8 teaspoon), Lime (2) to a blender. Blend until smooth.
Pour the mixture into a shallow dish. Freeze for 1 hour.
Remove from the fridge and scrape the mixture with a fork to break up the frozen parts, especially along the sides. Return to the fridge and freeze for another hour. Repeat every hour or so, until the mixture is dry and completely made up of frozen, almost-fluffy ice crystals, it should take around 4 hours total but will depend on the size of your dish.
Serve in small bowls or cups, garnished with lime zest, Sea Salt Flakes (to taste), and a blueberry.